Computer Simulation of Polarization vs. Electric-Field Curves of Non-Linear Dielectrics and Macromodel for SPICE simulator

Abstract

Nonlinear dielectrics such as ferroelectrics, relaxors and frequency-tunable capacitors are desired to be handled in circuit simulators such as the SPICE. We have developed a software package to simulate a wide variety of nonlinear dielectrics in the SPICE. In the simulation of the polarization vs. electric field curve (P-E curve), the program code ''P-E simulator'' divided the P-E curve into two parts, a nonlinear dielectric part and a domain-switching part. In the former, the polarization was calculated as a linear expansion in terms of electric field, while in the latter, the polarization due to domain switching was calculated by assuming that the distribution of domain-switching probability was represented by Gaussian distribution functions. Two Gaussian distribution functions were required to accurately simulate the P-E curves of ferroelectric materials with the 180-degree and the non-180-degree domains. A circuit model with two capacitors and an arbitrary voltage source was proposed for a macromodel of nonlinear dielectrics in the SPICE. The netlist data to the SPICE were automatically generated using the program code ''Mk-netlist'' from the parameters determined using the P-E simulator. The P-E curves of a PZT thin film and multilayered ceramics capacitors were successfully simulated in the SPICE without the trial-and-error process.

Mechanism Underlying Stacking-Layer Effect of Dielectric Properties of Multilayer Ceramic Capacitors

“…They were separated and shown in Fig. 5(b) in accordance with the report by Kubota et al 15,16) It should be noted that the stress effect was observed only in the nonlinear dielectric part of the P-E curve. In the core-shell structure of X7R-MLCCs, the core part is almost pure BaTiO 3 with ferroelectricity depressed by the size effect of BaTiO 3 , while the shell part is composed of dielectrics with nonlinear dielectricity.…”

Mechanism of Capacitance Aging under DC Electric Fields in Multilayer Ceramic Capacitors with X7R Characteristics

“…The nonlinear permittivity of MLCCs can be handled using a circuit simulator such as SPICE. 18) If the capacitance change with time is not acceptable in the relatively short period, the domain-wall motion in the core should be clamped completely by stable defects. The multivalence ions like Mn may not be suitable for this purpose.…”

Influence of Schottky Interfaces on Dielectric Properties in Perovskite-Type Oxide Thin-Film Capacitors

“…Ferroelectric (hysteretic) response to the applied voltage is generally explained in terms of domain switching. The domain-switching is depicted using a Gaussian function f p that describes switching probability as a function of applied electric field [8]:…”